1). Field of the Invention
The present invention relates generally to testing of semiconductor chip packages and, more specifically, to a pickup chuck which is used in combination with a contactor for purposes of testing a semiconductor chip package, and to a method of making electrical contact between a semiconductor chip package and a contactor.
2). Discussion of Related Art
FIG. 1 of the accompanying drawings shows a conventional semiconductor chip package 10 comprising a package substrate 12 and a semiconductor chip 14 located on the package substrate 12. An integrated circuit is located within the semiconductor chip 14. The integrated circuit is placed in electrical communication with the package substrate 12 via an array of solder balls 16. Electrical leads 18 lead through the package substrate 12 to a set of contact pads 20 on an opposing surface of the package substrate 12. A semiconductor chip such as the semiconductor chip 14 of FIG. 1 is usually tested after being located on the package substrate 12 and before being shipped out.
FIG. 2 illustrates diagramatically a portion of a conventional pickup chuck 26, for purposes of picking up a semiconductor chip package 10 such as in FIG. 1, defining a recess 28. The pickup chuck is positioned over the semiconductor chip package 10 with the semiconductor chip package 10 located within the recess 28 and seating on an inner surface 30 of the recess 28. Suction pads or the like (not shown), are then operated so as to retain the semiconductor chip package 10 within the recess 28. Utilizing the pickup chuck 26, the semiconductor chip package 10 is then transported to a contactor which is electrically connected to an electrical test unit.
FIG. 3 illustrates the pickup chuck 26 which is used in combination with a contactor 32 for purposes of electrically connecting the contact pads 20 to the electric test unit. The contactor 32 has a locating formation 34 therein which receives the pickup chuck 26, and a set of pogo pins 36, located within the locating formation 34, each of which making contact with a respective contact pad 20. Electrical leads 38 extend from the pogo pins 36 and eventually end up within the electric test unit. The semiconductor chip 14 is thus electrically connected to the test unit via the array of solder balls 16, the electric leads 18, the contact pads 20, the pogo pins 36, and the electric leads 38. Two of the electric leads 38A and 38B are respectively connected to a power source and electric ground for purposes of supplying electric power to the semiconductor chip 14 and supplying the semiconductor chip 14 with electric ground. Note that the electric power and electric ground are supplied to the semiconductor chip package 10 via two of the contact pads 20, all of the contact pads being located on a single surface of the package substrate 12.
FIG. 4 illustrates recent developments in the technology of Intel Corporation of Santa Clara, Calif. wherein electric contacts are provided on opposing surfaces of the package substrate. FIG. 4 shows a semiconductor chip package 50 which includes a package substrate 52 and a semiconductor chip 54 located on the package substrate 52. Electric connection between an integrated circuit within the semiconductor chip 54 and the package substrate 52 is made via an array of solder balls 56. The package substrate 52 is made in layers which include a first metal layer 58 and a second metal layer 60. The first and second metal layers 58 and 60 each has a exposed region at the end of the package substrate 52. The exposed regions are positioned so as to form a first electric contact 62 on a chip side of the package substrate 52 and a second electric contact 64 on a non-chip side of the package substrate 52. First and second electric leads 66A and 66B connect the semiconductor chip 54 electrically to respectively the first metal layer 58 and the second metal layer 60. Electric power is supplied to the semiconductor chip 54 by application of a power source to the first electric contact 62, and electric ground is supplied to the semiconductor chip 54 by application of electric ground to the second electrical contact 64. More electric leads 68 extend through the package substrate 52 to contact pads 70 on the non-chip side of the package substrate 52. The contact pads 70 serve to provide logic communication to the semiconductor chip 54.
It can thus be seen that the semiconductor chip package 50 has electric contacts on opposing sides thereof, as opposed to the semiconductor chip package 10 of FIG. 1 which only has electric contact pads on one side thereof. A test arrangement is therefore required which can make contact with all contacts. Although the description that follows is primarily directed at apparatus for purposes of handling the semiconductor chip package 50 of FIG. 4, it should be understood that the invention resides in the broader concept of making electric contact with contacts on opposing sides of a semiconductor chip package, regardless of the exact positioning or purpose of the contacts.